1. When sliding down the height h, the vertical velocity change during this period is superimposed with the initial velocity vector, and then the relative velocity is superimposed with the implicated velocity (slope velocity) vector.

This moment of inertia is very basic. . .

3.( 1) Find the definite integral. . .

(2) Using the above answers, the kinetic energy theorem comes out.

(3) Yes. According to the loop theorem (the chapter of curve integral), the conservative force condition is satisfied.